Frame structures of a frame protocol layer of an Iub/Iur Frame Protocol (FP) can be divided into a data frame and a control frame according to uses. The control frame is used to transmit control information between a Serving Radio Network Control (SRNC) and a Node B, wherein the control frame used to carry uplink outer loop power control information is called as an outer loop power control frame.
FIG. 1 shows the transmitting process of the outer loop power control frame, which is transmitted from the SRNC to the Node B via an Iub/Iur interface by the frame protocol layer. The SRNC measures the transmission quality of data transmitted from the Node B, and dynamically adjusts a SIR Target value according to the transmission quality, which is indicated in the SIR TARGET domain of the outer loop power control frame; and the SIR Target value is used for the process of an uplink inner loop power control. The Node B measures an actual uplink SIR value received, compares it with the SIR Target value sent to the Node B by the SRNC, and adjusts the uplink transmission power of a current user equipment (UE) according to the result of the comparison. Specifically, if the measured SIR value is less than a target SIR value, the Node B will notify the UE to increase the transmission power; and if the measured SIR value is more than the target SIR value, the Node B will notify the UE to reduce the transmission power. By means of this process, the SRNC is enabled to control the uplink transmission power of the UE; and the communication quality of each link can basically remain at a set value.
FIG. 2 shows the frame structure of the above outer loop power control frame which carries the uplink outer loop power control information and is transmitted between the SRNC and the Node B. The outer loop power control frame comprises the following two parts:
(1) a head comprising the following three domains:
a CRC checking code domain, which has a length of 7 bits, is located from bit 7 to bit 1 of the first byte of the head of the frame, and is used to represent checking code(s) generated from the part of the frame excluding the CRC checking code domain according to a checking code generating formula;
a frame type indication domain, which has a length of 1 bit, is located at bit 0 of the first byte of the head of the frame, and is used to indicate whether the frame is the data frame or the control frame; and since the outer loop power control frame belongs to the control frame, the corresponding bit of the domain is “1”; and
a control frame type domain, which has a length of 8 bits, is located in the second byte of the frame head, and is used to represent the type of the control information;
(2) a payload comprising the following 2 domains:
a SIR TARGET domain, which has a length of 1 byte, is located in the first byte of a payload part, and used to indicate the SIR Target value of the uplink inner loop power control; wherein the SIR Target value is determined by the SRNC according to the result of comparing the current data transmission quality with the SIR Target value, the range of the SIR Target value that can be represented is {−8.2 dB, . . . , 17.3 dB}, and the corresponding relations between mapped values of the domain and SIR Target values are illustrated in Table 1 as follows:
TABLE 1UL_SIR_TARGETSIR Target000−8.2 dB001−8.1 dB002−8.0 dB. . .. . .25417.2 dB25517.3 dB
and a rest extending domain, which has a length from 0 to 32 bytes and is used for extending new information elements (IE).
With the introduction of a High Speed Uplink Packet Access (HSUPA) technology, a terminal will be enabled to transmit data on N (N is more than or equal to 1) carriers at the same time. The uplink transmission power of the UE is the sum of the uplink transmission power of all the carriers, and each of the carriers will independently perform an uplink transmission power control, i.e., the Node B needs to independently adjust the transmission power of each of the uplink carriers of the UE, therefore, the Node B needs to acquire the SIR Target values corresponding to each of the carriers, i.e., in an uplink N (N is more than or equal to 1) carrier system, relationships between the carriers and the SIR Target values need to be included in the uplink outer loop power control information.
If the outer loop power control frame structure in the prior art is used to carry the uplink outer loop power control information, after dynamically adjusting the SIR Target values of each of the carriers, the SRNC can only carry the SIR Target value by the SIR TARGET domain of the outer loop power control frame, and can not carry information associated with the carriers or information of relationships between the SIR Target values and the carriers. Therefore, the Node B can neither judge that an inner loop power control of which carrier is performed by means of the SIR Target value indicated by the SIR TARGET domain in the current outer loop power control frame nor judge the uplink transmission power of which carrier is to be adjusted according to the uplink outer loop power control information carried in the outer loop power control frame structure. As a result, relationships between the carriers and the SIR Target values can not be acquired; and the inner loop power control can not be performed on a certain carrier either.
Effective solutions have not been proposed for the problems in the related art that in an N carrier HSUPA system, the relationships between the carriers and the SIR Target values can not be acquired and an independent uplink transmission power control can not be performed to the carriers.